Brush-holder.



No. 851,793. PATENTED APR. 80, 1907. R. R- BARKER,

BRUSH HOLDER.

APPLICATION FILED HOV.13,1903.

- Inventor. M Ralph ii-Barker. MW RR Witnesses THE NoRnls PETERS CQ UNITED STATES PATENT OFFICE.

RALPH E. BARKER, OF LYNN MASSACHUSETTS, ASSIGNOP. TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

BRUSH-HOLDER Specification of Letters Patent.

Patented April 30, 1907.

To all whom it 'ntag concern:

Be it known that I, RALPH E. BARKER, a citizen of the United States, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Brushd lolders, of which the following is a specification.

In ordinary commutating dynamo-electric machines it is frequently desirable to vary the lead of the current-collecting brushes. For instance, when the direction of rotation of the machine is reversed it is desirable to reverse the lead.

My present invention has for its object the provisi on of an improved form of brush-sup porting means so constructed that the lead of the brushes may be readily varied.

My invention consists in certain features of construction and arrangement which will be fully pointed out in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawings in which I have illustrated one embodiment of my invention.

Of the drawings, Figure 1 is an end elevation and Fig. 2 is a side elevation of a dynamo-electric machine; Fig. 3 is a sectional elevation on the line 3 3 of Fig. 2.

In the drawings, 1 represents a dynamoelectric machine provided with a field ring 2 from which integral supporting feet 3 project. Members 4 and 5 are secured at opposite ends of the ring 2. The members 1 and 5 are provided with bearings in which the armature-shaft 6 is journaled.

The member 4 is formed with a bell-shaped portion 7, which incloses the commutator 8. Bosses 9 having openings or sockets 10 formed in them pro ect from opposite sides of the bell-shaped portion 7. These openings or sockets, which. may be cylindrical, are in line with one another and extend perpendicularly to the shaft 6.

A brush-holder 11 is placed in each socket 10. The brush-holders are in the form of bushings which are preferably formed of some insulating material such as hard rubber or the like. The bushings are formed each with a portion 12 which -lits one of the openings 10, and with a flange portion 13, which abuts against the outer ends of the bosses 9. In the construction shown in the drawings, the busljiings are formed with outer portions 14 which are smaller in diameter than the portions 12 and are placed eccentrically with respect to them.

A metallic box or tube member 15, which is shown as having a bore of rectangular cross section, is placed in an opening formed for the purpose in each bushing. These boxes are eccentrically located with respect to the portions 12 of the brush-holder but may be concentrically placed with respect to the portions 1 1. The boxes are secured in place in the bushings in any suitable manner, as by means of pins 16. Suitable brushes 17, which may be formed of carbon, are placed in the boxes. The inner ends of these brushes bear against the commutator when the bushings are in position. Plugs 18, which may be formed of suitable insulating material, such as wood, are secured in place in the outer ends of the boxes. Suitable springs are located in the boxes be tween the inner ends of the plugs 18 and the outer ends of the bushings 17. These springs hold the brushes against the commutator with. the proper amount of pressure. Each box carries a clamping screw 19 by which a current-carrying conductor or lead may be secured to the box.

W hen the bushings which form the brushholders are assembled on the bosses 9, they are arranged so that the brush at the left, for instance, in F 3 is near the upper side of the boss 9, and the brush which is to the right in Fig. 3 is near the lower side of the boss 9. When it is desired to reverse the direction of rotation of the armature, the bushings will be shifted so that the brush at the left of Fig. 3 will be nearer the lower part of the boss 9, while the brush on the right of Fig. 3 will be nearer the upper part of the boss 9. By properly proportioning the parts the change in position of each brush with respect to the commutator, which will be double the eccentricity of the brush with respect to the portion 12 of the holder, will be sullicient for the proper operation of the machine in the reverse direction of rotation.

As shown in Fig. 3, diametrically opposed key-ways 20 may be formed in each holder. Suitable pins or keys 21. carried by the bosses 9 co-operate with the key-ways 20 to properly position the holders in the bosses. in

order to obtain the proper change in position of each brush when it is desired to reverse the LII direction of rotation of the motor, it is only 1 necessary to remove each holder, give it a sockets, and brushes eccentrically mounted iii said bushings.

2. In a dynamo electric machine, a commutator, a cooperating brush, a holder for the brush, a support for the holder, and means tor interchange-ad lv securing the 1 brush-holder rigidly to the support in either This 'liile my invention is generally applicable to coiiiinutatiiig machines, it is particularly intended for use in connection with small motors which are ordinarily or at least frequently controlled by operators possessing but little skill. My invention provides a means by which the connections to the motor and the position of the brushes may be altered by such process with compa-rative ease and safety.

hat I claim as new and desire to secure by Letters Patent ol the United States, is,

1. In combination with a lyiiaiiio-electric machine provided with a commutator, a casmg or supportingmember provided with two j sockets, bushings removably secured in said i of two operative positions, to give a brush lead in one direction or the other.

3. .ln combination, a brush-holder and a support therelor toriiied with a socket into which the brush-holder may be inserted in dill'erent positions, and a brush located eccentrically in said holder whereby by varying the position of the brush-holder in said socket the lead given to the brush can be varied or reversed.

t. In a dynamo-electric machine, a support provided with a socket, a brush, and means for securing said brush in ditl'erent portions oi said socket.

In a tlyiiaiiio-electric machine, a supiport provided with a socket, a brush and holder therefor, and means for securing said holder iii said support in ditiereiit positions. In witness whereol', l have hereunto set my hand this tenth dav of November, 1903.

PouiPti E. BARKER. -Witnesses:

DUoi-uin Moli. Mcliiriiioi JOHN A. MCBIANUS. 

